The atmosphere of a workstation may be controlled to have a certain temperature, humidity, pressure and/or chemical composition. For example, a controlled atmosphere workstation may have a normoxic, hypoxic, anoxic or anaerobic atmosphere, where the oxygen concentration is controlled.
To monitor the oxygen concentration of a controlled atmosphere, conventional workstations typically comprise an oxygen sensor. It is known that the accuracy of the oxygen sensor can deteriorate over time. Therefore, to avoid a degradation of performance, the oxygen sensor is calibrated on a regular basis.
One known way of calibrating an oxygen sensor involves removing the oxygen sensor from the workstation and conducting the calibration process remotely. However, it has been found that the removal of the oxygen sensor increases the risk of sensor damage, may cause thermal shock and lead to the formation of condensation of the sensor surface. This approach also results in significant down-time, disrupting the operation of the workstation.
In an alternative approach, calibration may involve manually calibrating an oxygen sensor whilst it remains in-situ within the workstation. However, this approach requires an operator to insert his arms into the workstation and so the size of the workstation is restricted to allow the operator to reach the oxygen sensor and manoeuvre the calibration apparatus. Human-error may occur when operating the calibration apparatus in restricted conditions and when following the complex, multi-step calibration procedure. There is also an increased risk that controlled atmosphere may escape or ambient air may enter the workstation during calibration.